Pub Date : 2023-10-05DOI: 10.20961/mekanika.v22i2.75062
A. C. P. T. Nugroho, C. Sasmito, Abid Paripurna Fuadi, Dany Hendrik, Cakra Wijaya Kusuma Rahadi, Rizqi Dian Permana, Noor Muhammad Ridha Fuadi
Corrosion is a major concern in the marine industry, compromising the safety and integrity of ships. This paper presents a corrosion rate analysis and prediction of the remaining life of the Baruna Jaya IV research vessel using non-destructive testing (NDT) ultrasonic testing to improve ship safety aspects. The NDT ultrasonic testing was conducted on the ship's hull to evaluate the thickness and detect any hidden corrosion. The results were used to develop a corrosion rate model and predict the remaining life of the ship using a probabilistic model. The study found that the corrosion rate of the ship was high, and the remaining life of the ship was estimated to be less than five years. The study’s findings can be used to develop a maintenance and repair strategy to reduce corrosion and improve the safety of the Baruna Jaya IV research vessel.
腐蚀是海运业的一个主要问题，会损害船舶的安全和完整性。本文介绍了使用无损检测（NDT）超声波测试对 Baruna Jaya IV 号研究船进行腐蚀率分析和剩余寿命预测，以改善船舶安全方面的问题。对船体进行了无损检测超声波测试，以评估船体厚度并检测任何隐藏的腐蚀。检测结果用于开发腐蚀率模型，并使用概率模型预测船舶的剩余寿命。研究发现，该船的腐蚀率很高，估计剩余寿命不到 5 年。研究结果可用于制定维护和修理策略，以减少腐蚀并提高巴鲁纳查亚IV号科考船的安全性。
{"title":"Corrosion Rate Analysis and Prediction of the Remaining Life of the Research Vessel to Improve Ship Safety Aspects","authors":"A. C. P. T. Nugroho, C. Sasmito, Abid Paripurna Fuadi, Dany Hendrik, Cakra Wijaya Kusuma Rahadi, Rizqi Dian Permana, Noor Muhammad Ridha Fuadi","doi":"10.20961/mekanika.v22i2.75062","DOIUrl":"https://doi.org/10.20961/mekanika.v22i2.75062","url":null,"abstract":"Corrosion is a major concern in the marine industry, compromising the safety and integrity of ships. This paper presents a corrosion rate analysis and prediction of the remaining life of the Baruna Jaya IV research vessel using non-destructive testing (NDT) ultrasonic testing to improve ship safety aspects. The NDT ultrasonic testing was conducted on the ship's hull to evaluate the thickness and detect any hidden corrosion. The results were used to develop a corrosion rate model and predict the remaining life of the ship using a probabilistic model. The study found that the corrosion rate of the ship was high, and the remaining life of the ship was estimated to be less than five years. The study’s findings can be used to develop a maintenance and repair strategy to reduce corrosion and improve the safety of the Baruna Jaya IV research vessel.","PeriodicalId":356258,"journal":{"name":"Mekanika: Majalah Ilmiah Mekanika","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139323284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-05DOI: 10.20961/mekanika.v22i2.75079
Yudiawan Fajar Kusuma, Ilham Hariz, Hanni Defianti, Buddin Al Hakim, Arfis Maydino F. Putra
As a country along the Pacific Ring of Fire, Indonesia faces various natural disaster threats, including tsunamis. Therefore, an early tsunami warning system is crucial for detecting potential tsunami waves. The early tsunami warning system encompasses several complex components, one of which is the Ocean Bottom Unit (OBU) floater. This paper discusses the performance of various types of floater arrays for tsunami early warning systems using Computational Fluid Dynamics (CFD) simulations. The study focuses on coefficients, especially the drag coefficient, and the influence of the number of float arrangements on the flow pattern around the buoy or Ocean Bottom Unit (OBU) array. Among the five numerical simulation models, the six-couple floater has the highest drag and lowest lift coefficients, while the single floater has the lowest drag coefficient. The percentage of difference in drag coefficient between single floater and couple series floater is quite significant, reaching up to 50%. The moment coefficient is also affected by the number of floaters, with a series of five couple floaters having the highest moment coefficient at a Reynolds (RE) number of 2 × 106. The advantage of using the CFD method is that it can visualize current velocity, which is crucial for understanding the flow pattern around the float system. The results indicate that the flow pattern becomes more complex as the number of floater arrays increases, which leads to more vortices between the floater, resulting in increased turbulence and drag coefficient.
{"title":"Predicting the Drag Coefficient Characteristics of Ocean Bottom Unit (OBU) Float Array Model for Early Warning Tsunami Systems Using Computational Fluid Dynamics (CFD) Method","authors":"Yudiawan Fajar Kusuma, Ilham Hariz, Hanni Defianti, Buddin Al Hakim, Arfis Maydino F. Putra","doi":"10.20961/mekanika.v22i2.75079","DOIUrl":"https://doi.org/10.20961/mekanika.v22i2.75079","url":null,"abstract":"As a country along the Pacific Ring of Fire, Indonesia faces various natural disaster threats, including tsunamis. Therefore, an early tsunami warning system is crucial for detecting potential tsunami waves. The early tsunami warning system encompasses several complex components, one of which is the Ocean Bottom Unit (OBU) floater. This paper discusses the performance of various types of floater arrays for tsunami early warning systems using Computational Fluid Dynamics (CFD) simulations. The study focuses on coefficients, especially the drag coefficient, and the influence of the number of float arrangements on the flow pattern around the buoy or Ocean Bottom Unit (OBU) array. Among the five numerical simulation models, the six-couple floater has the highest drag and lowest lift coefficients, while the single floater has the lowest drag coefficient. The percentage of difference in drag coefficient between single floater and couple series floater is quite significant, reaching up to 50%. The moment coefficient is also affected by the number of floaters, with a series of five couple floaters having the highest moment coefficient at a Reynolds (RE) number of 2 × 106. The advantage of using the CFD method is that it can visualize current velocity, which is crucial for understanding the flow pattern around the float system. The results indicate that the flow pattern becomes more complex as the number of floater arrays increases, which leads to more vortices between the floater, resulting in increased turbulence and drag coefficient.","PeriodicalId":356258,"journal":{"name":"Mekanika: Majalah Ilmiah Mekanika","volume":"58 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139322969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-05DOI: 10.20961/mekanika.v22i2.76502
Hidayatus Ubyani, T. Tuswan, H. Yudo, Haris Nubli, O. Mursid, Muhammad Iqbal
The project planning process, especially in ship repair projects, is essential to improving project completion. Ineffective planning of ship repair projects results in a lack of time and labour efficiency. Therefore, using project acceleration tools in scheduling ship repair activities is crucial to accelerate project completion and mitigate risk analysis of delays for each project activity. This research uses the critical path method (CPM) to analyze the main schedule of three combined ship repair projects. Then, shop-level planning is used to determine the productivity of each workshop so that each workshop knows the volume of work that needs to be completed daily. Furthermore, fuzzy logic is applied to analyze the risk of delays in repair project activities. The addition of working hours to critical work activities is accelerated from 30 days, the normal duration, to 23 days. Meanwhile, the addition of the workforce to critical work activities is accelerated from 30 days, the normal duration, to 22 days. The analysis of productivity values in each workshop results in the following productivity values: sandblasting and painting workshop 309.97 m2/person-days, piping workshop 4.12 units/person-days, fabrication workshop 407.16 kg/person-days, outfitting workshop 14.8 units/person-days, tank cleaning workshop 114.36 m3/person-days, and machining workshop 2.7 units/person-days. The fuzzy logic analysis results to determine the risk of delays in critical activities show that jobs with the codes SP1, SP2, SP3, SP4, M2, and SP5 have a high risk of delay. Additionally, the collaboration with other departments in the company, such as the marketing, finance, and human resources departments, is ongoing to complete assigned tasks.
{"title":"Repair Project Acceleration Strategy of Three Ship Units using Fuzzy Logic Analysis and Critical Path Method","authors":"Hidayatus Ubyani, T. Tuswan, H. Yudo, Haris Nubli, O. Mursid, Muhammad Iqbal","doi":"10.20961/mekanika.v22i2.76502","DOIUrl":"https://doi.org/10.20961/mekanika.v22i2.76502","url":null,"abstract":"The project planning process, especially in ship repair projects, is essential to improving project completion. Ineffective planning of ship repair projects results in a lack of time and labour efficiency. Therefore, using project acceleration tools in scheduling ship repair activities is crucial to accelerate project completion and mitigate risk analysis of delays for each project activity. This research uses the critical path method (CPM) to analyze the main schedule of three combined ship repair projects. Then, shop-level planning is used to determine the productivity of each workshop so that each workshop knows the volume of work that needs to be completed daily. Furthermore, fuzzy logic is applied to analyze the risk of delays in repair project activities. The addition of working hours to critical work activities is accelerated from 30 days, the normal duration, to 23 days. Meanwhile, the addition of the workforce to critical work activities is accelerated from 30 days, the normal duration, to 22 days. The analysis of productivity values in each workshop results in the following productivity values: sandblasting and painting workshop 309.97 m2/person-days, piping workshop 4.12 units/person-days, fabrication workshop 407.16 kg/person-days, outfitting workshop 14.8 units/person-days, tank cleaning workshop 114.36 m3/person-days, and machining workshop 2.7 units/person-days. The fuzzy logic analysis results to determine the risk of delays in critical activities show that jobs with the codes SP1, SP2, SP3, SP4, M2, and SP5 have a high risk of delay. Additionally, the collaboration with other departments in the company, such as the marketing, finance, and human resources departments, is ongoing to complete assigned tasks.","PeriodicalId":356258,"journal":{"name":"Mekanika: Majalah Ilmiah Mekanika","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139323061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-05DOI: 10.20961/mekanika.v22i2.76968
Supa Kusuma Aji, Nicky Suwandhy A. S, C. Gunawan, Bayu Pranoto, Hangga Wicaksono
Two-phase flows consisting of liquids and gases are often found in everyday life and are used on an industrial scale. In an industrial environment, this flow has many weaknesses, including pressure drop and void fraction. One strategy to reduce losses that arise is to use passive methods. The passive method used is to utilize the shape of the grooves in the channel. In this study, the flow is used to determine its effect on the pressure drop and void fraction that appears in two-phase flow. The experimental method was used for this study. The test pipe is equipped with 16 grooves, while the smooth pipe (without grooves) is used as a comparison. The test pipe is made of acrylic material. The water fluid is circulated using a centrifugal water pump with a superficial speed of 0.33-0.42 m/s. Air fluid is supplied using a compressor with superficial speeds of 0.049, 0.066, and 0.082 m/s. Measurement of pressure drop was carried out using a pressure transmitter with an Arduino data logger. The void fraction is calculated by determining the ratio of the volume fraction of water and air in the test tube. The results of the study revealed that the use of 16 grooves in the pipe can reduce the pressure drop and cavity fraction that appears when compared to smooth pipes.
{"title":"Pressure Drop and Void Fraction of Two-Phase Flow (Air-Water) in Grooved Vertical Pipes","authors":"Supa Kusuma Aji, Nicky Suwandhy A. S, C. Gunawan, Bayu Pranoto, Hangga Wicaksono","doi":"10.20961/mekanika.v22i2.76968","DOIUrl":"https://doi.org/10.20961/mekanika.v22i2.76968","url":null,"abstract":"Two-phase flows consisting of liquids and gases are often found in everyday life and are used on an industrial scale. In an industrial environment, this flow has many weaknesses, including pressure drop and void fraction. One strategy to reduce losses that arise is to use passive methods. The passive method used is to utilize the shape of the grooves in the channel. In this study, the flow is used to determine its effect on the pressure drop and void fraction that appears in two-phase flow. The experimental method was used for this study. The test pipe is equipped with 16 grooves, while the smooth pipe (without grooves) is used as a comparison. The test pipe is made of acrylic material. The water fluid is circulated using a centrifugal water pump with a superficial speed of 0.33-0.42 m/s. Air fluid is supplied using a compressor with superficial speeds of 0.049, 0.066, and 0.082 m/s. Measurement of pressure drop was carried out using a pressure transmitter with an Arduino data logger. The void fraction is calculated by determining the ratio of the volume fraction of water and air in the test tube. The results of the study revealed that the use of 16 grooves in the pipe can reduce the pressure drop and cavity fraction that appears when compared to smooth pipes.","PeriodicalId":356258,"journal":{"name":"Mekanika: Majalah Ilmiah Mekanika","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139323298","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-05DOI: 10.20961/mekanika.v22i2.75378
S. Sudarno, Quang Thang Do, Haris Nubli, Dandun Mahesa Prabowoputra, Nur Candra Dana Agusti, Ridwan Ridwan, Anggi Vandika
This review article presents a comprehensive overview of welding, including its environmental influence, common welding failures, welding parameters, and predictions of development regarding welding and corrosion. The quality and integrity of welds can be significantly affected by environmental factors such as temperature, humidity, and atmospheric contaminants. Moreover, welding failures can occur due to various reasons, such as improper welding techniques, inadequate preparation, corrosion, or material defects, leading to structural weaknesses and compromised joint integrity. Furthermore, notable progress has been achieved in welding system technology, encompassing automation, robotics, and real-time monitoring. These advancements underscore the vital role of welding parameters in transforming control, precision, and productivity within the welding process. The integration of innovative welding systems has led to improved welding efficiency, reduced human error, and increased overall process reliability. This review consolidates knowledge from diverse sources, making it a valuable resource for researchers, practitioners, and industries involved in welding.
{"title":"Evaluating the Influence of Environmental Factors and Parameters on Advancements in Welding and Joining Processes: A Review","authors":"S. Sudarno, Quang Thang Do, Haris Nubli, Dandun Mahesa Prabowoputra, Nur Candra Dana Agusti, Ridwan Ridwan, Anggi Vandika","doi":"10.20961/mekanika.v22i2.75378","DOIUrl":"https://doi.org/10.20961/mekanika.v22i2.75378","url":null,"abstract":"This review article presents a comprehensive overview of welding, including its environmental influence, common welding failures, welding parameters, and predictions of development regarding welding and corrosion. The quality and integrity of welds can be significantly affected by environmental factors such as temperature, humidity, and atmospheric contaminants. Moreover, welding failures can occur due to various reasons, such as improper welding techniques, inadequate preparation, corrosion, or material defects, leading to structural weaknesses and compromised joint integrity. Furthermore, notable progress has been achieved in welding system technology, encompassing automation, robotics, and real-time monitoring. These advancements underscore the vital role of welding parameters in transforming control, precision, and productivity within the welding process. The integration of innovative welding systems has led to improved welding efficiency, reduced human error, and increased overall process reliability. This review consolidates knowledge from diverse sources, making it a valuable resource for researchers, practitioners, and industries involved in welding.","PeriodicalId":356258,"journal":{"name":"Mekanika: Majalah Ilmiah Mekanika","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139322989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-05DOI: 10.20961/mekanika.v22i2.71340
M. A. Mohd Rosli, S. D. Prasetyo, Dominicus Danardono Dwi Prija Tjahjana, Alfian Fahrul Yuliansyah, Zainal Arifin
Several methods to enhance heat transfer can be classified into three categories: active, passive, or hybrid. Among these methods, Vortex Generators (VGs) are one passive heat transfer enhancement device widely used in heat exchangers. This study aims to explore the geometric shapes of VGs equipped with longitudinal holes and examine their influence on the outlet temperature of the fluid. For the analysis in this research, a three-dimensional Computational Fluid Dynamics (CFD) simulation using ANSYS Fluent software was employed. The increased heat transfer and flow resistance in the VG geometry were evaluated based on previous research for validation. The study results demonstrate that the simulation produces fluid outlet temperature values and velocity contours that closely resemble the results obtained from the reference study. The validation error of this research was found to be only 0.02%, indicating high-quality and accurate simulation results. Furthermore, the study compared various geometries of the VG holes in the system. Among these geometries, hexagonal-shaped VG holes exhibited high-velocity contours on the VG side while achieving the lowest fluid outlet temperature at approximately 303.53 K. The findings of this study serve as a basis for further developments in enhancing the efficiency and performance of heat exchangers using VGs.
{"title":"Effect of Hole Geometry Shape in Vortex Generators on Fluid Output Temperature: Computational Fluids Dynamics Validation","authors":"M. A. Mohd Rosli, S. D. Prasetyo, Dominicus Danardono Dwi Prija Tjahjana, Alfian Fahrul Yuliansyah, Zainal Arifin","doi":"10.20961/mekanika.v22i2.71340","DOIUrl":"https://doi.org/10.20961/mekanika.v22i2.71340","url":null,"abstract":"Several methods to enhance heat transfer can be classified into three categories: active, passive, or hybrid. Among these methods, Vortex Generators (VGs) are one passive heat transfer enhancement device widely used in heat exchangers. This study aims to explore the geometric shapes of VGs equipped with longitudinal holes and examine their influence on the outlet temperature of the fluid. For the analysis in this research, a three-dimensional Computational Fluid Dynamics (CFD) simulation using ANSYS Fluent software was employed. The increased heat transfer and flow resistance in the VG geometry were evaluated based on previous research for validation. The study results demonstrate that the simulation produces fluid outlet temperature values and velocity contours that closely resemble the results obtained from the reference study. The validation error of this research was found to be only 0.02%, indicating high-quality and accurate simulation results. Furthermore, the study compared various geometries of the VG holes in the system. Among these geometries, hexagonal-shaped VG holes exhibited high-velocity contours on the VG side while achieving the lowest fluid outlet temperature at approximately 303.53 K. The findings of this study serve as a basis for further developments in enhancing the efficiency and performance of heat exchangers using VGs.","PeriodicalId":356258,"journal":{"name":"Mekanika: Majalah Ilmiah Mekanika","volume":"93 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139322830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-05DOI: 10.20961/mekanika.v22i2.71250
Shazia Hanif, Suryadijaya Adiputra, I. Yaningsih, E. P. Budiana
The utilization of RD-type silica gel material as an adsorbent within the Personal Protective Equipment (PPE) layer underwent a comprehensive analysis aimed at elucidating its unique adsorption characteristics through the application of MATLAB programming. This study aims to determine the characteristics of silica gel RD to water vapor in terms of adsorption capacity and rate. A layer modeling approach was employed to simulate the Personal Protective Equipment (PPE), which comprised four distinct layers: the surrounding environment air, the fabric layer, the RD-type silica gel layer, and the air gap separating the silica gel from the skin surface. The simulation encompassed environmental conditions set at 27℃, while the human body's temperature was maintained at 35℃. This study uses a simulation method using GAB (Guggenheim–Anderson–de Boer) modeling calculations to determine isothermal characteristics and LDF (Linear Driving Force) modeling to determine kinetic characteristics with an adsorbent temperature of 26.84℃. The simulation results show that the isothermal characteristics of silica gel RD at a relative humidity of 60% or a relative pressure of 0.6 have an absorption capacity of 0.38 kg/kg. Moreover, the kinetic characteristics of silica gel RD have an absorption rate of 0.38 kg/kg of water vapor with a time of 980 s until a significant reduction in the absorption value occurs.
{"title":"Adsorption Characteristics of Silica Gel-Water Pairs in Personal Protection Equipment","authors":"Shazia Hanif, Suryadijaya Adiputra, I. Yaningsih, E. P. Budiana","doi":"10.20961/mekanika.v22i2.71250","DOIUrl":"https://doi.org/10.20961/mekanika.v22i2.71250","url":null,"abstract":"The utilization of RD-type silica gel material as an adsorbent within the Personal Protective Equipment (PPE) layer underwent a comprehensive analysis aimed at elucidating its unique adsorption characteristics through the application of MATLAB programming. This study aims to determine the characteristics of silica gel RD to water vapor in terms of adsorption capacity and rate. A layer modeling approach was employed to simulate the Personal Protective Equipment (PPE), which comprised four distinct layers: the surrounding environment air, the fabric layer, the RD-type silica gel layer, and the air gap separating the silica gel from the skin surface. The simulation encompassed environmental conditions set at 27℃, while the human body's temperature was maintained at 35℃. This study uses a simulation method using GAB (Guggenheim–Anderson–de Boer) modeling calculations to determine isothermal characteristics and LDF (Linear Driving Force) modeling to determine kinetic characteristics with an adsorbent temperature of 26.84℃. The simulation results show that the isothermal characteristics of silica gel RD at a relative humidity of 60% or a relative pressure of 0.6 have an absorption capacity of 0.38 kg/kg. Moreover, the kinetic characteristics of silica gel RD have an absorption rate of 0.38 kg/kg of water vapor with a time of 980 s until a significant reduction in the absorption value occurs.","PeriodicalId":356258,"journal":{"name":"Mekanika: Majalah Ilmiah Mekanika","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139323027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-05DOI: 10.20961/mekanika.v22i2.76774
Ridwan Ridwan, S. Sudarno, Haris Nubli, Achmad Chasan, Iwan Istanto, Pandu Sandi Pratama
As the demand for lightweight ships continues to rise, there is a growing necessity to explore innovative methods that can reduce the weight of ship structures without altering the materials used. This research addresses this challenge by investigating the effect of opening in stiffener under impact loading. The research aims to provide valuable insights into optimizing weight reduction strategies while ensuring the ship's overall strength and performance remain uncompromised. To achieve this goal, the study employed the finite element method as a solver. By simulating impact scenarios and analyzing stiffener responses, the numerical analysis quantified the structural behavior and failure modes. The focus was on understanding the impact of openings on the structural integrity and how it relates to their positioning relative to the impact point. The results of the study indicate that opening slightly distant from the impact point exhibit greater strength, showcasing a counterintuitive relationship between opening placement and structural response.
{"title":"Numerical Analysis of Openings in Stiffeners under Impact Loading: Investigating Structural Response and Failure Behavior","authors":"Ridwan Ridwan, S. Sudarno, Haris Nubli, Achmad Chasan, Iwan Istanto, Pandu Sandi Pratama","doi":"10.20961/mekanika.v22i2.76774","DOIUrl":"https://doi.org/10.20961/mekanika.v22i2.76774","url":null,"abstract":"As the demand for lightweight ships continues to rise, there is a growing necessity to explore innovative methods that can reduce the weight of ship structures without altering the materials used. This research addresses this challenge by investigating the effect of opening in stiffener under impact loading. The research aims to provide valuable insights into optimizing weight reduction strategies while ensuring the ship's overall strength and performance remain uncompromised. To achieve this goal, the study employed the finite element method as a solver. By simulating impact scenarios and analyzing stiffener responses, the numerical analysis quantified the structural behavior and failure modes. The focus was on understanding the impact of openings on the structural integrity and how it relates to their positioning relative to the impact point. The results of the study indicate that opening slightly distant from the impact point exhibit greater strength, showcasing a counterintuitive relationship between opening placement and structural response.","PeriodicalId":356258,"journal":{"name":"Mekanika: Majalah Ilmiah Mekanika","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139323226","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-31DOI: 10.20961/mekanika.v22i1.44371
J. Cho, Ridwan Ridwan, Rama Panji Kusuma, J. Triyono, N. Muhayat, Aprianur Fajri, Fajar Budi Laksono
The bus driver's comfort is crucial. The location of the driver's seat, which is correlated with the seat support design, is one of the elements supporting his comfort. The bus business chosen as a representative is PT Selamet Trans Abadi, which has its headquarters in Pati City, Central Java. By considering the Safety Factor, House of Quality (HOQ), weight, shape, and seat support dimensions, this study intends to ascertain how the characteristics of the bus seat support form after receiving a load or force. Conducting a field visit to gather the necessary data is the initial step in this research. The following stage is to decide on the design criteria based on the collected data. Next, use Solidwork to model the design. Using the Finite Element Method (FEM), this program can investigate design characteristics. The loading simulation under consideration includes clutch engagement, bus brake application, and clutch engagement, whether the support is static or stationary. The validation with two supporting journals is then run as the following step to validate the findings. The constant chair support fulfills the typical value, according to the study's findings, whereas support 1 is the most fracture-prone. The outcomes of supports 2 and 3 demonstrate that the support strength is weak since it is subjected to an unequal load.
公共汽车司机的舒适度至关重要。驾驶员座椅的位置与座椅支撑设计相关，是支撑驾驶员舒适性的要素之一。被选为代表的巴士企业是PT Selamet Trans Abadi，其总部位于中爪哇的帕蒂市。通过考虑安全系数、质量屋(HOQ)、重量、形状和座椅支撑尺寸，本研究旨在确定公交车座椅支撑在接受载荷或力后的特性。进行实地考察以收集必要的数据是这项研究的第一步。接下来的阶段是根据收集到的数据确定设计标准。接下来，使用Solidwork建模设计。利用有限元法(FEM)，该程序可以研究设计特征。所考虑的负载模拟包括离合器接合、公共汽车制动应用和离合器接合，无论支承是静态的还是静止的。然后使用两个支持期刊进行验证，作为验证发现的以下步骤。根据研究结果，恒定的椅子支撑满足典型值，而支撑1是最容易骨折的。支座2和支座3的计算结果表明，由于受不等荷载作用，支座强度较弱。
{"title":"Design Analysis and Structural Prediction of Bus Driver Chair Support: A Study Case using HOQ and FEM","authors":"J. Cho, Ridwan Ridwan, Rama Panji Kusuma, J. Triyono, N. Muhayat, Aprianur Fajri, Fajar Budi Laksono","doi":"10.20961/mekanika.v22i1.44371","DOIUrl":"https://doi.org/10.20961/mekanika.v22i1.44371","url":null,"abstract":"The bus driver's comfort is crucial. The location of the driver's seat, which is correlated with the seat support design, is one of the elements supporting his comfort. The bus business chosen as a representative is PT Selamet Trans Abadi, which has its headquarters in Pati City, Central Java. By considering the Safety Factor, House of Quality (HOQ), weight, shape, and seat support dimensions, this study intends to ascertain how the characteristics of the bus seat support form after receiving a load or force. Conducting a field visit to gather the necessary data is the initial step in this research. The following stage is to decide on the design criteria based on the collected data. Next, use Solidwork to model the design. Using the Finite Element Method (FEM), this program can investigate design characteristics. The loading simulation under consideration includes clutch engagement, bus brake application, and clutch engagement, whether the support is static or stationary. The validation with two supporting journals is then run as the following step to validate the findings. The constant chair support fulfills the typical value, according to the study's findings, whereas support 1 is the most fracture-prone. The outcomes of supports 2 and 3 demonstrate that the support strength is weak since it is subjected to an unequal load.","PeriodicalId":356258,"journal":{"name":"Mekanika: Majalah Ilmiah Mekanika","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131907807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-31DOI: 10.20961/mekanika.v22i1.70884
Irvian Adhana, D. F. Smaradhana, D. Ariawan, W. W. Raharjo, Burhanuddin Yusuf
Acrylonitrile Butadiene Styrene (ABS) polymer is an example of a thermoplastic polymer that requires heat in its production process. ABS polymer also can be modified to increase strength against resistance, toughness, and heat resistance by adding MCC as a reinforcement to ABS composites. Extrusion is one of the established methods of polymer processing with filler and consequently disperses filler inside the polymer. Different speed shows different behavior of filler dispersion. Therefore, this study was conducted to know the effect of extruder screw speed variations on the mechanical, physical, and thermal stability of ABS/MCC composites. The compositions used in producing ABS/MCC composites are 96% for ABS and 4% for MCC. The production process uses screw extruder speed variations of 10 rpm, 15 rpm, and 20 rpm. ABS/MCC composite in the barrel and hot press use 160 °C for the temperature process. The highest tensile strength was obtained at 10 rpm variation for 14.2 MPa. Increasing the speed of the extruder screw causes a decrease in MCC content attached to ABS which reduces the mechanical strength. ABS/MCC composite density value decreased with the increased extruder speed, as evidenced by the increasing number of voids formed based on SEM testing.
{"title":"Effect of Screw Rotation Speed on Mechanical Properties and Morphology of Abs/Mcc Composites","authors":"Irvian Adhana, D. F. Smaradhana, D. Ariawan, W. W. Raharjo, Burhanuddin Yusuf","doi":"10.20961/mekanika.v22i1.70884","DOIUrl":"https://doi.org/10.20961/mekanika.v22i1.70884","url":null,"abstract":"Acrylonitrile Butadiene Styrene (ABS) polymer is an example of a thermoplastic polymer that requires heat in its production process. ABS polymer also can be modified to increase strength against resistance, toughness, and heat resistance by adding MCC as a reinforcement to ABS composites. Extrusion is one of the established methods of polymer processing with filler and consequently disperses filler inside the polymer. Different speed shows different behavior of filler dispersion. Therefore, this study was conducted to know the effect of extruder screw speed variations on the mechanical, physical, and thermal stability of ABS/MCC composites. The compositions used in producing ABS/MCC composites are 96% for ABS and 4% for MCC. The production process uses screw extruder speed variations of 10 rpm, 15 rpm, and 20 rpm. ABS/MCC composite in the barrel and hot press use 160 °C for the temperature process. The highest tensile strength was obtained at 10 rpm variation for 14.2 MPa. Increasing the speed of the extruder screw causes a decrease in MCC content attached to ABS which reduces the mechanical strength. ABS/MCC composite density value decreased with the increased extruder speed, as evidenced by the increasing number of voids formed based on SEM testing.","PeriodicalId":356258,"journal":{"name":"Mekanika: Majalah Ilmiah Mekanika","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126485190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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